<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml" xmlns:v-bind="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>列表渲染</title>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/axios@0.12.0/dist/axios.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/lodash@4.13.1/lodash.min.js"></script>
</head>
<body>

<ul id="example-1">
    <li v-for="item in items" :key="item.id">
        {{ item.message }}
    </li>
</ul>

<ul id="example-2">
    <li v-for="(item, index) in items">
        {{ parentMessage }} - {{ index }} - {{ item.message }}
    </li>
</ul>

<div id="example-3">
    <li v-for="n in evenNumbers">{{ n }}</li>
</div>

<div id="todo-list-example">
    <form v-on:submit.prevent="addNewTodo">
        <label for="new-todo">Add a todo</label>
        <input
                v-model="newTodoText"
                id="new-todo"
                placeholder="E.g. Feed the cat"
        >
        <button>Add</button>
    </form>
    <ul>
        <li
                is="todo-item"
                v-for="(todo, index) in todos"
                v-bind:key="todo.id"
                v-bind:title="todo.title"
                v-on:remove="todos.splice(index, 1)"
        ></li>
    </ul>
</div>

<script>

    var example1 = new Vue({
        el: '#example-1',
        data: {
            items: [
                { message: 'Foo' },
                { message: 'Bar' }
            ]
        }
    })

    var example2 = new Vue({
        el: '#example-2',
        data: {
            parentMessage: 'Parent',
            items: [
                { message: 'Foo' },
                { message: 'Bar' }
            ]
        }
    })

    var example3 = new Vue({
            el: '#example-3',
            data: {
                numbers: [ 1, 2, 3, 4, 5 ]
            },
            computed: {
                evenNumbers: function () {
                    return this.numbers.filter(function (number) {
                        return number % 2 === 0
                    })
                }
            }
        })

    Vue.component('todo-item', {
        template: '\
    <li>\
      {{ title }}\
      <button v-on:click="$emit(\'remove\')">Remove</button>\
    </li>\
  ',
        props: ['title']
    })

    new Vue({
        el: '#todo-list-example',
        data: {
            newTodoText: '',
            todos: [
                {
                    id: 1,
                    title: 'Do the dishes',
                },
                {
                    id: 2,
                    title: 'Take out the trash',
                },
                {
                    id: 3,
                    title: 'Mow the lawn'
                }
            ],
            nextTodoId: 4
        },
        methods: {
            addNewTodo: function () {
                this.todos.push({
                    id: this.nextTodoId++,
                    title: this.newTodoText
                })
                this.newTodoText = ''
            }
        }
    })


</script>

</body>
</html>